Dynamic skew correction in a multi-lane communication link

Abstract

A mechanism for dynamic skew correction in a multi-lane communication link includes a receiver unit including, for each of the lanes, a first-in first-out (FIFO). The FIFO may store received symbols to locations pointed to by a write pointer and output to downstream logic, symbols stored at locations pointed to by a read pointer. The receiver may also include a symbol drop unit that disables the write pointer in response to receiving a start alignment symbol, and enables the write pointer in response to receiving an end alignment symbol. The receiver also includes an alignment unit that disables the read pointer in response to detecting that the end symbol has been received at least one lane but not all lanes. In addition, the alignment unit may enable the read pointer in response to a determination that the end symbol has been received on all lanes.

Description

BACKGROUND[0001]1. Technical Field[0002]This disclosure relates to communication links, and more particularly to dynamic skew correction in multi-lane links.[0003]2. Description of the Related Art[0004]Many communication links employ multiple communication lanes that operate simultaneously. In such an environment, lane to lane skew may be problematic. The skew may be expressed as a difference in arrival time of bit streams on each lane at the receiver's side, even though the bit streams were transmitted simultaneously at the transmitter side. Generally, the skew may be classified as either static or dynamic and each may be caused by a variety of factors.[0005]For example, one source of static skew may be wiring trace length variations between lanes, whether the traces are on a circuit board or an integrated circuit. Another source may be wire bond impedance variations between lanes. Another source of static skew may be variations in clock domain crossing latencies between lanes from...

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